As a result of the recent development of electronics, there is a rapid increase in the demand for semiconductor devices such as memories and integrated circuits.
Such a semiconductor device is manufactured by doping impurities into a highly pure semiconductor substrate to impart electrical properties thereto, and forming a minute circuit on the semiconductor substrate by etching, for example.
Such operations must be performed in a chamber in a high-vacuum state to avoid the influence of dust or the like in the air. A vacuum pump is generally used to evacuate the chamber. In particular, a turbo-molecular pump, which is a kind of vacuum pump, is widely used since it involves little residual gas and is easy to maintain.
When manufacturing a semiconductor, these are many steps for making various process gases act on a semiconductor substrate, and the turbo-molecular pump is used not only to create a vacuum in a chamber, but also to discharge these process gases from the chamber.
This turbo-molecular pump consists of a pump main unit and a control device for controlling the pump main unit. Generally, the pump main unit and the control device are connected through a cable and a connector plug mechanism. As a method for simplifying wiring between substrates by reducing the number of pins of connector plugs for connecting the pump main unit and the control device, Patent Literature 1 suggests that a control substrate for a motor and a magnetic bearing should be arranged on the vacuum side.